Fountain pen



April 10, 1934. F. .1. SCHISLER FOUNTAIN PEN (PISTON TYPE) Filed Dec. 15, 1933 j/T/a/ Iwvemior fig 77/ 5A 0777/89.? Mai/4 Patented Apr. 10, 1934 UNITED STATES PATENT OFFICE FOUNTAIN PEN (PISTON TYPE) Frank J. Schisler, Minneapolis, Minn. Application December 15, 1933, Serial No. 702,505

8 Claims. (01. 120-47) This invention relates to self-filling fountain pens and more particularly to those of the piston type wherein the interior of the barrel is utilized for a reservoir for ink.

It is an object of my invention to provide a simplified and improved fountain pen of the type referred to wherein substantially the entire interior of the barrel may be filled with writing fluid by withdrawal of the piston in a rearwardly direction while permitting escape of air from the rearward side of the piston in the filling stroke through a controlled vent extending to the exterior of the barrel through the feed member.

It is a further object to provide a self-filling pen of the class described which, while holding a maximum supply of writing fluid will effect a uniform feeding of that fluid to the nib regardless of the amount of fluid standing in the reservoir or barrel.

More specifically it is an object to provide a fountain pen of the class described having a piston slidably mounted in the barrel for the purpose of filling the pen by suction through the ink feed and having a system of passages and valves associated with the piston so constructed and related that the air behind the piston may escape through an independent air vent during the filling action and that the air vent may be closed and the valves controlling ports through the piston will be simultaneously opened to enable the piston to be returned to normal position adjacent the feed member of the pen.

A further object isthe provision, in such a fountain pen, of feed mechanism working on a barometric feed or vacuum principle whereby a uniform feed to the nib is assured regardless of the volume of ink in the reservoir.

These and other objects and advantages of the invention will be more fully set forth in the following description made in connection with the accompanying drawing, in which like reference characters refer to similar parts throughout the several views, and in which:-

Fig. 1 is a section taken longitudinally through an embodiment of my invention with the piston in normal position for writing;

Fig. 2 is a cross section taken on the line 2-2 of Fig. 1 showing the liquid ports in the valve disks and the piston proper in communication;

Fig. 3 liquid ports through the piston closed by the valve disks and the air discharge ports through the disk and piston proper in communication to facilitate filling of the reservoir;

is a similar cross section showing the Fig. 4 is a perspective view of the piston and the two valve disks detached, and

Fig. 5 is a plan view showing the opposite side of the piston to that shown in Fig. l.

The embodiment of my invention illustrated includes an elongated cylindrical barrel 6 which may be constructed of any suitable hard, noncorrosive material, such as hard ruber, Bakelite or non-corrosive metal. If constructed of transparent or translucent material, the amount of ink standing in the reservoir may be readily ascertained.

The forward end of this barrel is closed by a suitable threaded plug 7 which carries the feed member 8 forming in conjunction with the plug a socket for releasably holding the nib or pen point 9. A feed passage 8a of conventional type is formed through the feed member 8 for supplying ink to the bottom of nib 9, said passage communicating with the interior of barrel 6.

A relatively small air tube 10 is axially disposed within barrel 6 and is threadedly and rigidly secured at its forward end in the rear portion of the feed member 8. An air vent 8b is formed through the feed chamber 8 communicating with the forward end of air tube 10 and communicates with the exterior of the pen and barrel through the peripheral wall of the feed member 8. Air vent 8b may be conveniently formed by drilling the rear end of feed member 8 axially and on a i reduced bore to that of the threaded socket for receiving air tube 10 and then drilling an obliquely disposed passage through the peripheral Wall of feed member 3 which communicates with the axial passage first drilled.

A slidable tube 11 surrounds the stationary air tube 10 and is spaced slightly and concentrically therefrom rotatively carrying at its forward end a piston 12 which is disposed between two valve disks 13 and 1% respectively, integrally formed or otherwise rigidly secured to the forward portion of said slidable tube. A suitable packing cup or gland indicated as an entirety by the numeral 15 is screw threaded or otherwise secured to the forward end of slidable tube 11 and surrounds stationary tube 10, the packing contained therein preventing passage of air or liquid between the forward end of tube 11 and the periphery of stationary air tube 10. Stationary tube 10 terminates somewhat short of slidable tube 11 when said tubes are in extreme telescoped position. The rear or outer end of slidable tube 11 extends through a plug 16 screw threaded or otherwise secured in the rear end of barrel 6 and carrying a packing gland 17, the packing material of which prevents passage of air or liquid between the periphery of slidable tube 11 and the plug 16. Slidable tube 11 is closed at its rear end and is pinned to a cap 18 which may be removably screw threaded upon the rear end of plug 16 and which acts as a handle for manipulating the piston when unscrewed or detached from said plug.

By means of a system of registrable ports, piston l2 and disks 13 and 14 cooperate to form first a valve operative to permit passage of fluid to the rear side of the plunger when the plunger is projected to normal position after suction of the ink into the reservoir and secondly a valve operative to permit escape of air from behind the plunger through the air tube 10 and air vent 81) when the plunger is moved in its suction stroke. To this end the plunger 12 is provided with a pair of circumferentially arranged ports 12a therethrough to permit passage of the writing fluid when the piston is projected toward the forward end of the barrel. Ports 12a are registrable with a pair of ports 14a in the rear valve disk 14 and with a pair of ports 13a. in valve disk 13. The disk 14 is also provided with an air port 14?) disposed inwardly of ports 140. which communicates with a radial passage 12b in piston 12, which, as shown, is formed by a groove on the rear face of the piston, said groove extending from an intermediate portion of the annular piston to the inner periphery thereof. Passage 12b is adapted to register with a port 11a. formed in the peripheral wall of the slidable tube 11 whereby communication of the chamber behind the piston with the interior of tube 11 is established for escape of air rearwardly through tube 11 and then through the stationary tube 10 and the air vent 8b. Oscillation of the valve disks 13 and 14 relative to the piston 12 is limited by means of a pin 19 fixed to the rear face of disk 13, which pin engages a radial slot 120 formed in the face of the piston.

Operation To fill my improved pen the cap 18 is unscrewed in counter-clockwise direction, turning withit the tube 11 and the valve disks 13 and 14. Piston 12 frictionally engages the interior of barrel 6 and the friction is sufficient to prevent piston 12 from turning until disks 13 and 14 have oscillated relative to the piston to their limit of movement, i. e., until the limiting pin 19 engages the end of slot 120 in the position indicated by the dotted lines in Fig. 3. When the cap is disengaged from the plug 16 the liquid ports 1211 are necessarily closed by the valve disks 13 and 14 and the pen is ready for filling. The plunger is then retracted by pulling the cap 18 rearwardly while the nib of the pen is immersed in an ink well or other source of supply. The tube 11 of course constitutes a piston rod. As ink is drawn into the reservoir formed by the barrel, the air behind the piston escapes through port 14b in the rear valve disk, through passage 12b and port 11a in tube 11, this air passing rearwardly through tube 11 and then into the stationary tube 10 and forwardly through said tube, being discharged through the air vent 8b in the feed member 8. All air is thus exhausted and consequently the entire interior of the reservoir formed by barrel 6 may be filled with writing fluid. The cap or handle 18 is then turned in clockwise rotation to open the liquid ports 1211 by relative oscillation of the valve disks l3 and 14 into the position shown in Fig. 2, this rotation of the sleeve 11 simultaneously causing the closure of the air escape port 121). The plunger is then projected to normal position by pushing the cap 18 inwardly toward the rear end of the barrel and in the projection of the plunger the ink is drawn through the ports 1241 into the chamber behind the piston due to the vacuum eifect produced by the forward projection of the plunger. The cap may then be screwed onto the plug 16 at the end of the barrel in clock-wise direction, still leaving the ink ports 12a open for supplying the nib with ink.

From the foregoing description it will be noted that when the pen is filled there will be substantially no air in the ink reservoir and air is admitted as the ink is consumed only through the feed passage 8a in the member 8. The ink feed is therefore based on the barometric seal principle and a uniform supply to the nib is assured. It further will be noted that gravity will have no effect in forcing out ink when the reservoir is full, first because of the vacuum effect obtained in the displacement of ink from behind the piston, and, secondly, because of the efficient construction of a feeding chamber provided just above the feed member 8 by the cooperation of certain of the elements of my device previously described. In writing position of the parts, the piston 12 is disposed a short distance above the inner end of plug 7 forming in conjunction with the forward end of the barrel 6 and the plug, a chamber 0 adapted to contain only a few drops of ink (for example, from 4 to 8 drops). The liquid ports 12a through the plunger are of relatively very small diameter and consequently, when the pen is held in writing position with the barrel extending upwardly, the vacuum effect above the level of the ink in the barrel will retain the ink from working into chamber C through the small ports 12a. Ink will be supplied to the nib from filling chamber C until the contents of said chamber are exhausted, air to displace the ink fed passing upwardly through the relatively large feed passage 8a. This air will not pass upwardly through the plunger due to the sealing of the ports 12a by the liquid in the reservoir. It is therefore necessary to occasionally tip the pen, disposing the nib end upwardly to uncover the ports through the plunger and permit entrance of air behind the piston. The pen may then be positioned for writing and filling chamber C will be replenished with ink. It will be seen, therefore, that the pressure from the weight of the ink in the small chamber C is negligible and substantially a uniform feed is obtained regardless of the amount of ink in the reservoir behind the piston.

I wish to stress the importance of my structure of the air vent including passage 8b in tubes 10 and 11, which is independent of the feed passage for the ink and disposed on the opposite side of the pen therefrom. With this independent air vent, in the filling of my pen, air is effectively discharged from behind the piston and will in no way interfere with the suction of ink and substantially all the air will be displaced and the reservoir loaded to capacity. With most forms of piston pen, air is mixed to some extent with the indrawn writing fluid and the reservoir consequently can only be loaded to partial ca- 4 before returning the piston to normal position, but will be readily reminded of this requirement if inadvertently he forgets, since he will notice a discharge of ink from the nib.

The structure of my pen affords an efficient means for readily cleansing the reservoir, the piston valves and the feeding passage through member 8. To accomplish this, water or other cleansing fluid is drawn into the barrel by the piston and the piston rod is maintained in filling position as the cleansing fluid is ejected, the valves of the piston being closed. The flushing of the barrel and feeding element is then similar to an ordinary syringe.

It will, of course, be understood that various changes may be made in the form, details, proportions and arrangement of the parts without departing from the scope of my invention, which, generally stated, consists in a device capable of carrying out the objects above set forth and in the novel parts and combinations of parts disclosed and defined in the appended claims.

In the appended claims, the term reciprocated is used with reference to the piston in its broad sense, including travel of the piston in the barrel toward and away from the nib end of the pen regardless of whether that movement is accompanied with rotative movements or not.

What is claimed is:-

1. In a fountain pen, a barrel constituting a reservoir, a feed member having a feeding passage, a piston having a valve associated therewith, means by which said piston may be reciprocated in the barrel, means forming an air vent independent of the passage through said feed member and communicable with the chamber behind said piston and means for controlling said valve and the communication of said air vent.

2. In a fountain pen, a barrel constituting a reservoir, a feed member having a feeding passage, a piston having a valve associated therewith, means by which said piston may be reciprocated in the barrel, said feed member having an independent air vent formed therethrough extending to the exterior of the pen, a stationary conduit mounted longitudinally within said barrel and communicating at its forward end with said air vent, said conduit extending through said piston and having an air intake opening adjacent the rear end of said barrel whereby escape of air will be effected in the rearward or filling movement of said piston.

3. In a fountain pen, a barrel constituting a reservoir, a feed member having a longitudinally extending feeding passage, a piston reciprocable in said barrel and having a relatively small li uid port therethrough, a tubular piston rod with which said piston is rotatably connected, a valve member non-rotatably connected with said tubular piston rod for controlling the opening and closing of said port by oscillation of said piston,

a conduit telescopically mounted within said piston rod, said feed member having an air vent communicating with the forward end of said conduit, the rear end of said conduit being in open communication with the interior of said tubular piston rod, said piston and said valve member having registering ports constituting a passage between the rear side of said piston and the interior of said tubular piston rod.

4. In a fountain pen, a barrel constituting a reservoir, a feed member having a longitudinally extending feed passage, a piston reciprocable in said barrel and having a relatively small liquid port therethrough, a piston rod with which said piston is rotatably connected, and a valve member non-rotatably connected with said piston rod for controlling the opening and closing of said port by oscillation of said piston.

5. In a fountain pen, a barrel constituting a reservoir, a feed member having a longitudinally extending feed passage, a piston reciprocable in said barrel and having a relatively small liquid port therethrough, a piston rod with which said piston is rotatably connected, a valve member non-rotatably connected with said piston rod for controlling the opening and closing of said port by oscillation of said piston, a handle member secured to the rear end of said piston and having detachable rotative locking engagement with the rear of said pen and being so associated with reference to said valve member and piston rod that said valve will necessarily be closed when said handle member is released from locking engagement.

6. In a fountain pen, a barrel constituting a reservoir and having an air tight closure at one end thereof, a feed member at the opposite end thereof, a piston reciprocable in said barrel and having a relatively small port therethrough to permit passage of writing fluid, means for limiting the movement of said piston in a direction toward said feed member to define a relatively small feeding compartment between said piston and said feed member, said piston having a valve associated therewith for controlling said port.

'7. In a fountain pen, a barrel constituting a reservoir, a feed member having a longitudinally extending feeding passage, a piston reciprocable in said barrel and having a valve associated therewith, a tubular piston rod connected with 25 said piston, a conduit telescopically mounted within said piston rod, said feed member having an independent air vent communicating with the forward end of said conduit, the rear end of said conduit being in open communication with the 130 interior of said tubular piston rod, and a valved passage between the rear of said piston and the interior of said tubular piston rod.

8. The structure set forth in claim '7 and a valve in said passage being controllable by the 135 oscillation of said piston rod.

FRANK J. SCHISLER. 

